Lawsuits will not solve the problem, which is: there is no easy way to identify who owns which rights in and to most pieces of music and there is no easy way to get a quote and pay them.
And as part of this, there’s no way to automate the process of figuring out whether some bit of user generated content is aboveboard or not.
For example, the composer of a famous hit song once emailed me the URL of a famous hit recording of it. It was hosted on his personal ISP account. He told me that the performer on the recording had said it was fine.
Everything about this set up was indistinguishable, on a technical level, from an unauthorized source, and yet he absolutely had at least some of the rights.
Or did he have the rights? Had he done it as work for hire? Had the famous singer really said that it was ok? If so did the famous singer even have the rights? And how could a web developer hosting user generated content write a program to figure this out?
On a personal level this songwriter was a maniac extremist about copyright. He was to the right of Satan on the topic of Napsterization.